Mantle short, wide (approx. 40-60% ML), slightly depressed dorsoventrally, rounded behind. Head in larvae half-retractable (up to midline of eye). Fins tongue-like in larvae, resembling fish fins in juveniles (ML >3.5 mm) and adults, consisting of a series of flexible muscular "rays" joined by thin transparent film. Fin in juveniles much shorter, in adults a little shorter, than mantle. Arms short, 4th pair longer and wider than others. Arm suckers small, in 2 rows in proximal, 4-6 rows in distal part of 1st-3rd arms, in 1-2 zig-zag rows on 4th arms. Tentacles in larvae (<4 mm) short, with very distinctive round club with 6 irregular rows of suckers; in juveniles (>6 mm) and adults long, retractable, with a short narrow club bearing 8-14 rows of very small suckers; no fixing apparatus. Buccal membrane with 7 lappets, with 12-15 minute suckers in 2 rows on lappets, connectives to 4th arms attached ventrally. Funnel cartilage straight, elongate. Gladius with long rachis and wide vane, without end conus.
Photophores on eyeball (one elongated) and ink sac (large, round, resembling a fried egg on a black frying pan); in adult males also dorsocaudally on the mantle. Ink sac photophore appearing in late larvae. Egg size approx. 1.5 mm. ML up to 9, usually to 5-6 cm.
One species in the Atlantic.